ARDEX X 3 Tile and Stone Mortar is a Portland cement-based, polymer-modified mortar with good bond strength and sag resistance and a 3-hour pot life. ARDEX X 3 mixes to a creamy, easy to apply thin set mortar that is water and weather resistant. ARDEX X 3 can be used to install quarry, ceramic and most natural stone* tiles on many common interior or exterior surfaces and also can be used for setting porcelain tile over interior, absorbent concrete and other cementitious surfaces. ARDEX X 3 is recommended for the installation of most tile sizes**, including mosaics, and is suitable for use over concrete floors with in-floor heating systems.